Packing device



Maly 31, 1932.

F, w. KENNEDY PACKING DEVICE Filed Aug. 8. 1930 Navi mxdxlmhk L .Tl l

Wim/fas."

@www

ill

ii'atented iiiilag FRANK W. KENNEDY, OF TRENTON, NEW JERSEY, ASSIGNOR 'lO DE LAVAL STEAM TUR-EINE GGMPANY, 0F TRENTON, NEW JERSEY, A CORPORATION 0F NEW JERSEY PACKING DEVICE Application filed August 8, 1930. SerialV No. 473,802.

This invention relates to a packing box rotary pump sha ft.

it has been customary to provide a packing for rotary pump shafts including a ilexible bellowslike elen'ient consisting of a corrugated metal cylinder made either of sheet metal or, in large sizes, being turned out ot' a. solid forging. Packings of this type generally work well but have two serious faults: first, any slight water hammer due to sudden closing of a valve or entrance of steam into the pump will cause the flexible element to buckle and fail; and, second, Contact of the element with hot steam which under certain conditions enters the pump, allects its tlexi bility whereby its life is considerablyv short ened.

1t is the object of the present invention to improve a packing device of thisl character so as to render it immune to the destructive conditions just mentioned.

In the accompanying drawing the ligure is a fragmentary axial section through a packing box associated with a pump and embodying the invention.

The pump casing, indicated at 2 houses an impeller L carried by the shaft t3 having suitable bearings in the casing. A ring 8 carried by the casing has welded or otherwise secured thereto at 1() a flexible element 1Q which may consist of :i corrugated sheet metal cylinder or a forging turned to form corrugations to provide flexibility. Under some conditions this element may be of rubber or the like in which case it need not be corrugatd. To the outer end of element 12 is secured a carbon or other equivalent ring 14 bearing upon a steel collar 16 rotating with the shaft.

The packing arrangement so far described constitutes the common construction which, as noted above, is subject to failure under the action of Water hammer or steam.

The improvement in this construction is etl'ected b v securing metallic or other rigid tube 18 comfcntrically with the shaft to the ring t at 2t), this tube having a restricted clearance with the collar 16 as indicated at o0 The tube lS effectively prevents the detrimental action of the water hammer since the shock can only reach the lexible element through the tortuous path including the restricted opening and the energy thereof is accordingly practically dissipated before reaching the element. Likewise steam can reach the element only through the same long course and since'water is ordinarily trapped therein overheating is prevented.

lVliat l claim and desire to protect by Leb ters Patent is:

l. A packing device for a casing and a shaft passing into the casing including a. flexible annular element supported by one and carrying means bearing on a surface carried by the other, and a rigid tube located between the flexible element and the shaft, and substantially cutting oli' free communication between the flexible kelement and the interior of the casing.

2. A packing device for a casing and a shaft passing into the casing including a flexible annular element supported by one and carrying means bearing on a surface carried by the other, and a rigid tube fixed relatively to the flexible element, located between the (lexible element and the shaft, and substantially cutting olf free coinlmmication between the flexible element and the interior of the casing.

3. A packing device for a casing and a shaft passing into the casing including a flexible annular element supported by the casing and carrying means bearing on a surface carried by the shaft, and a rigid tubesupported by the casing between the flexible element and the shaft. and substantially cutting ofi' free connnunication between the flexible element and the interior ot the casing.

4. A packing device for a casing and a shaft passing into the casing including a flex-k ible corrugated metallic element supported by the casing and carryin means bearing on a this/filth day of 

